#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>

#include <iostream>
#include <thread>
using namespace std;
int main() {
  std::thread t([]() {
    std::cout << "Hello ! my id is " << (long int)syscall(SYS_gettid)
              << std::endl;
    ;
    sleep(20);
  });
  cout << sizeof t << endl;
  cout << t.get_id() << endl;
  t.join();
  return 0;
}
// g++ -o thread thread.cc -std=c++11